This invention relates to a method of automatically welding utilizing a non-consumable electrode with inert gas shielding, and more particularly, to a method utilizing arc voltage to control the rate at which filler wire is added to the weld.
Manually controlled, automatic welding devices have been developed for making repair to inaccessible areas utilizing fiber optic systems to observe the weld so that the operator can control the travel speed of the torch and the rate at which filler wire is added depending on the appearance of the weld puddle.
Automatic voltage control systems herebefore utilized moved the electrode with respect to the puddle to maintain a constant arc voltage and prevent contamination of the electrode with filler metal or improper bead shape.
Repair welding of locally removed defects in automatic welding processes is commonly done manually. Automatic equipment can be applied to do the rewelding, but wire addition proposes a programming problem. The present alternatives are to activate and deactivate the filler wire manually or to program the equipment to apply filler wire at the specific location and in the required amount. The manual repair relies on operator skill and his ability to closely observe the weld puddle as it proceeds into an area requiring filler metal and to reprogram a programmable welding apparatus is presently not in the skill of ordinary programmers.